Evaluation of functional properties of offal proteins

Evaluation of functional properties of beef heart and lip tissue proteins was based on the data obtained in the following determinations: protein extractability, fat emulsifying capacity, emulsion stability, gel forming ability, and water holding capacity after heat treatment. Beef skeletal muscles were used as the control. It was found that extractability of proteins of the raw materials was low as well as their ability to stabilize emulsions was on a low level. Proteins soluble at high ionic strength (fraction HIS) of beef heart and lip tissue emulsified 80.7 ml and 68.9 ml of oil/100 mg of protein, respectively, as compared to 106.6 ml in the control group. Analogically, protein soluble at low ionic strength (fraction LIS) emulsified 77.9 ml, 61.2 ml and 100.4 ml of oil, respectively. Emulsion stability of offal proteins appeared to be dependent on ionic strength. Generally at higher concentrations of salt their ability to stabilize emulsions was better as well as their water holding capacity increased. Their gelation properties as compared to control were also low. In each case, the functionality of cardiac proteins proved to be better than that of beef lip tissue.     

The structure and electro‐mechanical properties of novel hybrid CNT/PANI nanocomposites

Electrically conductive elastomeric nanocomposites containing carbon nanotubes (CNT) and polyaniline (PANI) are reported in the present investigation. The synthesis procedure included an in situ inverse emulsion polymerization of aniline doped with dodecylbenzene sulfonic acid (DBSA) in the presence of CNT and dissolved styrene‐isoprene‐styrene (SIS) block copolymer. The PANI synthesis step was carried out by applying ultrasonic energy. The dispersions obtained were processed by two methods: a recently developed precipitation‐filtration procedure, and a conventional drop‐cast procedure. The techniques developed resulted in homogeneous exfoliated PANI coated nanotubes within the elastomeric matrix. The presence of CNT/PANI in the SIS elastomeric matrix affects thermal, mechanical, and electrical properties of the nanocomposites. The formation of continuous three‐dimensional CNT/PANI networks prepared via the precipitation‐filtration method enhances the nanocomposite properties. Contrarily, the intermittent three‐dimensional network prepared by conventional drop‐cast method leads to inferior properties. Nanocomposites produced by both techniques are observed by HRSEM. The two processing techniques result in different structures, which affect the physical properties of the materials produced. A relatively low percolation threshold for both methods was determined. The Young's modulus of the SIS/CNT/PANI significantly increased in the presence of CNT. The precipitation‐filtration technique yields an improved nanocomposite product compared to the drop‐cast route. POLYM. COMPOS., 35:788–794, 2014. © 2013 Society of Plastics Engineers     

Supplier ranking by multi-alternative proposal analysis for agile projects

Changing requirements and on-going decision making along the entire project life cycle are well handled by Agile methods. However Agile projects still use evaluation methods during the RFP stage that do not fulfill the flexibility mandated by the Agile manifesto.     

Microwave plasma‐initiated grafting of acrylic acid on Celgard 2500 membrane to prepare alkaline battery separators—Characteristics of process and product

A process of plasma‐initiated grafting of acrylic acid on commercial porous polypropylene membrane was studied. The influence of parameters of the plasma (power, gas pressure, time plasma‐sample distance, sample arrangement) and grafting (solvent composition, monomer concentration, time, inhibitor presence) on the degree of grafting, amount of homopolymer produced and surface electrical resistance was determined. A degree of grafting up to 18 mmol/g was obtained, which resulted in sample resistance as low as 30 mΩ cm². The molecular weight of AAc homopolymer that can be assumed as equal to the MW of grafted chains, ranged from 25,000 to 50,000,000 da. SEM and water permeability measurements show that grafting causes filling of the pores, which, however, does not stop K⁺ ions from penetrating the membrane. The performance of nickel‐cadmium cells with acrylic acid grafted membranes as separator is also presented. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Accelerated weathering of pectin/poly(vinyl alcohol) blends studied by spectroscopic methods

The blends of pectin (PEC) and poly(vinyl alcohol) (PVA) at different components ratios were prepared by mixing in water. Thin polymeric films of PEC/PVA blends and pure polymers were obtained by casting method. All samples were then artificially aged using Suntest apparatus (Atlas) up to 780 h. The changes in chemical structure during sample ageing have been monitored by infrared and ultraviolet‐visible absorption spectroscopies. The first stage of weathering (up to ～ 300 h) was very slow and alteration of chemical structure was negligible in all samples. Prolonged ageing (>300 h) caused more significant degradation processes. FTIR spectra exhibited the highest changes in hydroxyl and carbonyl band ranges indicating the efficient photooxidation of macromolecules. The mechanisms of the observed processes have been discussed. It was found that PVA undergoes faster photoxidative degradation than pectin aged at the same conditions. The PEC/PVA blends exhibited the improved resistance to weathering comparing with both polymers aged individually. Mutual stabilization effect can be explained by intermolecular interactions between PEC and PVA confirmed by spectroscopic methods. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cytotoxicity of new Ho(III) and Pr(III) complexes

New complexes of coumarin-3-carboxylic acid (HCCA) with Ho(III) and Pr(III) were synthesized and their structures and spectral properties were investigated by elemental analysis, IR, Raman and NMR measurements. According to the experimental data the complexes' formula and geometries were suggested. Vibrational frequencies, IR intensities and Raman activities as well as ¹H NMR chemical shifts of HCCA and its Ho(III) and Pr(III) complexes were presented. The comparative experimental vibrational and NMR analyses of both the ligand and the Ln(III) complexes predicted the bidentate binding to Ho(III) and Pr(III) through the deprotonated carboxylic oxygen and the carbonylic oxygen of the ligand. The cytotoxic/cytostatic properties of the ligand and the newly synthesized complexes of coumarin-3-carboxylic acid with Ho(III) and Pr(III) were tested by MTT reduction assay against two mouse tumor cell lines: melanoma B16 and fibrosarcoma L929. They were also tested for cytotoxicity against normal mouse peritoneal macrophages. The proliferation inhibitory effect of the complexes compared to that of the ligand proved their cytotoxic/cytostatic properties against both the tumor cell lines. In addition, the complexes were less cytotoxic against normal mouse macrophages and were able to modulate NO release by activated macrophages. The obtained results were in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.     

Stability of cefacetrile in milk samples with various fat content

The consumers should have access to food that is safe and free of contaminants. Unfortunately, the wide use of antibiotics in livestock, not only for medicinal purposes but also as illegal feed additives, may be the reason for emergence of the antibiotic residues in foodstuffs of animal origin. Milk is one of the most essential nutrients for humans during their lifetimes. Failure of the withdrawal periods, or what is highly prohibited but in spite of this increasingly practiced, addition of the antibiotics to milk in order to prolong its freshness, may lead to occurrence of their residues. Cefacetrile is a first generation cephalosporin that is commonly use for the treatment of bovine mastitis. The aim of this work was to determine the stability of cefacetrile in milk samples of different fat content, that is, 0 , 2 , 3.2 % UHT, 2 % pasteurized and ~3.9 % raw cattle milk, for 5 days. Two chromatographic methods were applied and compared for this purpose, that is, thin-layer chromatography and high-performance liquid chromatography. According to the results coming from HPLC-UV analysis, the stability of cefacetrile increase with the increase in the fat mass content in UHT milk. The cefacetrile level in pasteurized and raw cattle milk is similar to that in 3.2 % UHT milk. For the TLC method, this relation can be observed only in the second day of the analysis. The spiked milk samples analyzed by HPLC were deproteinized with MeCN and stored for 5 days of the experiment. Whereas, in the TLC-UV method, the spiked milk samples prepared in the first day of experiment were analyzed directly, without deproteinization. The lower stability of cefacetrile in milk samples observed from the TLC analysis can be related to its partial enzymatic decomposition.     

Difference in subsurface damage in indented specimens with and without bonding layer

This paper aims to assess the applicability of the bonded–interface technique (BIT) that has been used for examining sub-surface damage in brittle materials. With the aid of the finite element method, the indentation stress fields in alumina specimens with and without a bonded–interface were analysed. It was found that the bonded–interface greatly alters the stress distribution in the neighbourhood of the interface. The high-stress zone shifts away from the interface, and extends to the surface. Both glue layer mechanical properties and bond thickness play a limited role in the overall stress field of the BIT alumina. Comparisons of theoretical predictions with experimental observations showed that, to a great extent, the BIT presents a different pattern of sub-surface damage. The study clarifies the applicability of the BIT and offers a useful guideline for practitioners.     

Strong stability of elastic control systems with dissipative saturating feedback

We will consider, with a focus on saturating feedback control laws, two problems associated with damping in a bounded acoustic cavity . Our objective is to verify (compare (Discrete Continuous Dynamical Systems 7 (2001) 319, Math. Control Signals Systems 2 (1989) 265) that these are strongly stable: for every finite-energy solution, the acoustic energy goes to zero as t→∞. We will, in each case, formulate the problem in terms of a contraction semigroup of nonlinear operators on an appropriate Hilbert space and compare this with the corresponding semigroups without saturation—following Avalos and Lasiecka (Semigroup Forum 57 (1998) 278) in using the spectral methods of Arendt and Batty (Trans. Amer. Math. Soc. 8 (1988) 837) to show strong stabilization for those linear semigroups.